The recording material employing color development through a reaction between a color former and a color-developing agent, since record may be made by a relatively simple apparatus in a short time without applying a complicated treatment such as development and fixation, are widely used in e.g., thermal recording paper for output-recording from a facsimile, a printer or the like, or pressure-sensitive copying paper of a ledger sheet for simultaneous copying to several sheets. As these recording materials, materials quickly developing color and keeping whiteness of uncolored part (hereinafter referred to as “background”) and providing highly robust colored images are desired, however, in view of long-term storage stability, a recording material providing background and images having excellent heat resistance is particularly desired. To attain this, it has been desired to develop a color former, a color-developing agent, a storage stabilizer and the like and thereby obtain a recording material having a further well-balanced color-developing sensitivity, background and image storage stability, etc.
In Patent Documents 1 to 3, it is described that a compound having a skeleton consisting of an alkylene group having at least a hydroxyl group and two benzene nuclei bound to the alkylene group, may be used as a sensitizer for a thermal recording material in combination with a specific color former and color-developing agent. Also in Patent Document 4, it is described that a non-phenol compound may be used as a color-developing agent.